This invention relates to a vehicle-mounted navigation system. Recently, navigation systems have been proposed that compute an optimal route from a starting point to a destination and guide a vehicle to the destination along the optimal route.
In the navigation system disclosed in Japanese Laid-Open Patent Application No. Hei 1-210819, eight arrows stored in a memory represent eight different directions spaced 45.degree. apart. The arrow representing the direction the driver should turn the vehicle to at the next intersection is selected and shown on a display. However, a problem arises where the driver encounters a forked intersection in the road. If the angle formed between two roads in the forked intersection is small, the navigation system disclosed in Japanese Laid-Open Patent Application No. Hei 1-210819 does not show the driver of the vehicle which of the two roads to choose.